JP4164406B2 - Radar device and similar device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radar device or sonar device that converts a detection signal received in a polar coordinate system into an orthogonal coordinate system and outputs the result to a display device, and more particularly to a device that outputs a scan correlation processing result of a detected target. is there.
[0002]
[Prior art]
A marine radar device transmits radio waves from a radar antenna, converts the received data of a polar coordinate system obtained by reflection from a target to an orthogonal coordinate system, stores the data in an image memory, and then displays it on a display by a raster scanning method. indicate. Here, the received data includes not only data reflected by the target object but also unnecessary components (hereinafter referred to as “clutter”) due to sea surface reflection or the like. For this reason, the conventional radar apparatus has a scan correlation processing function for repeatedly performing correlation between the current received data obtained during one rotation of the radar antenna and the previous scan correlation processing data. By performing this process, sudden data such as clutter can be removed, and only the received data from the necessary target can be displayed.
[0003]
A conventional structure of a radar apparatus that performs such scan correlation processing will be described with reference to FIG.
[0004]
FIG. 9 is a block diagram showing a main part of a conventional radar apparatus with scan correlation processing.
The radar antenna 101 transmits a pulsed radio wave to the outside at a predetermined transmission / reception period while rotating the horizontal plane at a predetermined rotation period, receives the radio wave reflected by the target with a polar coordinate system, and outputs a reception signal to the reception unit 102 Then, sweep angle data is output to the drawing address generation unit 105. The receiving unit 102 detects and amplifies the received signal from the radar antenna 101 and outputs it to the AD converting unit 103. The AD conversion unit 103 converts the analog reception signal into a digital signal (reception data) composed of a plurality of bits. The sweep memory 104 stores received data for one sweep that has been digitally converted in real time, and stores the received data for one sweep in the correlation data generation unit 107 until the received data obtained by the next transmission is written again. Output.
[0005]
As shown in FIG. 2, the drawing address generation unit 105 reads the antenna angle θ and the sweep memory 104 from the center of the sweep as the start address and from the center to the periphery with reference to a predetermined direction (for example, the bow direction). From the position r, an address for designating the pixels of the image memory arranged in the corresponding orthogonal coordinate system is created. Specifically, the drawing address generation unit 105 is configured by hardware that realizes the following equation.
[0006]
X = Xs + r · sin θ
Y = Ys + r · cos θ
However,
X, Y: Address that specifies the pixel of the image memory
Xs, Ys: Central address of sweep
r: Distance from the center
θ: Sweep (antenna) angle
The FIRST / LAST detection unit 106 first applies this sweep to each pixel of the orthogonal coordinate system set by the drawing address generation unit 105 on the correlation processing image memory 108 during one rotation of the sweep (radar antenna 1). The time of access or the time of last access is detected, and one of these timings is given to the correlation data generation unit 107. This is because it is necessary to limit the update of each pixel of the image memory for scan correlation processing to only once per sweep rotation, and therefore, the FIRST signal or the LAST signal is used as this timing.
[0007]
The correlation data generation unit 107 stores the received data input from the sweep memory 104 based on the FIRST signal (or LAST signal) input from the FIRST / LAST detection unit 106 and the correlation processing image memory 108 described later. The scan correlation processing is performed using the image data before one rotation of the sweep, and is stored in the correlation processing image memory 108 again.
[0008]
Here, for example, the scan correlation process corresponds to the received data obtained up to the previous time, which is input from the correlation processing image memory 108, with the received data input from the sweep memory 104 being N (t). Assuming that the correlation processing image data at the pixel position is W (t−1), the correlation processing image data W (t) during one rotation this time is calculated using the following equation.
[0009]
W (t) = α · N (t) + β · W (t−1)
Here, α and β are arbitrary numbers, and the contents of the scan correlation process can be changed by changing the values of α and β.
The correlation processing image memory 108 has a capacity for storing reception data (correlation processing image data) for one rotation of the sweep (radar antenna 1), and the correlation processing image data before one rotation is stored for the scan correlation processing. Feedback is provided to the correlation data generation unit 107. Further, when the display 109 is raster scanned by a display control unit (not shown), the correlation processing image memory 108 outputs correlation processing image data in synchronization with the raster scanning. Here, by changing the luminance and display color according to the data value for each pixel data of the correlation processed image data, the operator recognizes the position and movement of the target using the image subjected to the scan correlation processing. (For example, refer to Patent Document 1).
[0010]
[Patent Document 1]
JP 11-352212 A
[0011]
[Problems to be solved by the invention]
However, in a conventional radar apparatus that performs scan correlation processing, when adjusting GAIN, STC, FTC, etc. during scan correlation, the radar antenna is rotated several times (α , Which is determined by the value of β), and during this time, the operator cannot easily determine the adjustment amount, and it takes time for adjustment and adjustment is difficult. In addition, when switching from the display using the raw received signal without performing the scan correlation processing to the display using the scan correlation processing image data, the above-described problem occurs because of the time of the antenna number rotation unit.
[0012]
In addition, if the selected scan correlation processing content is not appropriate, the image to be suppressed may be emphasized and conversely the image to be emphasized may be suppressed. When such a state is judged and changed to the optimal processing content However, as described above, a predetermined time is required.
[0013]
In addition, the content of scan correlation processing differs between other ships moving at high speed and fixed targets such as coasts. When scanning correlation processing is used to emphasize fixed targets, images of other ships moving at high speed are suppressed. There is a possibility that. That is, if the fixed target is emphasized, the moving target is suppressed, and conversely, if the moving target is emphasized, the fixed target is suppressed.
[0014]
An object of the present invention is to gradually approach an image that has not been subjected to scan correlation based on received data that is currently being received, to an image that has undergone scan correlation processing, or to perform different scan correlation processing from an image that has undergone certain scan correlation processing. It is to provide a radar device and a similar device that can immediately observe a desired image by gradually approaching the executed image.
[0015]
Another object of the present invention is to output received data currently being received and scan correlation processed image data in parallel, or to output two pieces of scan correlation processed image data having different contents in parallel. It is another object of the present invention to provide a radar apparatus and a similar apparatus that can immediately output an image of the above.
[0016]
[Means for Solving the Problems]
The radar device and the similar device according to the present invention generate scan correlation processing data by performing correlation processing between the pixel data of the current received data obtained by rotating the sweep and the previous data of the stored pixel data. Scan correlation processing means, receiving data and scan correlation processing data are input, the received data is output as image data at a predetermined timing during one rotation of the sweep, and the received data and scan correlation processing are performed at a period other than the predetermined timing It is characterized by comprising transition image data generating means for generating transition data having values between them based on the data and outputting the data as image data.
[0017]
In this configuration, the timing at which the received data in the polar coordinate system accesses each pixel area of the image memory in the orthogonal coordinate system first or last is detected, and this timing signal is input to the scan correlation processing means and the transition image data generating means. Is done. Based on this timing signal, the scan correlation processing means generates and updates the current scan correlation processed image data using the current received data and the previously stored previous scan correlation processed image data. The transition image data generating means inputs the input raw reception data and the scan correlation processed image data, and selects the raw reception data when the timing signal is input during one rotation of the sweep (antenna). The image data based on the received data and the scan correlation processed image data are written into the image memory with a radial drawing address, which will be described later, and the scan correlation processed image data and the received data are used during a period when the timing signal is not input. Transition data that is in a state between and is generated and written to the image memory at a raster rendering address described later. In parallel with these drawing operations, the data is read out in synchronization with the scanning of the display and displayed as an image on the display. The generation of the transition data is repeated until the next timing signal for the corresponding pixel is input. As a result, the display unit displays an image that gradually changes from raw received data to scan correlation processed image data over time.
[0018]
Further, the radar device and the similar device of the present invention perform a correlation process between the pixel data of the current received data obtained by rotating the sweep and the previous data of the stored pixel data, respectively, and perform scan correlation. First and second scan correlation processing means for generating processing data, first scan correlation processing data generated by the first scan correlation processing means, and second generated by the second scan correlation processing means And the second scan correlation processing data is output as image data at a predetermined timing during one rotation of the sweep, and the first and second scan correlation processing data are output during a period other than the predetermined timing. And a transition image data generating means for generating transition data having values between them based on the output and outputting them as image data. There.
[0019]
In this configuration, the timing at which the received data in the polar coordinate system accesses each pixel area of the image memory in the orthogonal coordinate system first or last is detected, and this timing signal is used as the first and second scan correlation processing means and the transition image. Input to the data generation means. The first and second scan correlation processing means respectively use the current received data and the previous scan correlation processed image data that has already been stored, based on the timing signal, respectively. Is generated and stored. The transition image data generating means inputs the first scan correlation processed image data input from the first scan correlation processing means and the second scan correlation processed image data input from the second scan correlation processing means. When the timing signal is input during one rotation of the sweep (antenna), the second scan correlation processed image data is selected, written to the image memory with a radial drawing address described later, and the timing signal is input. A state between the second scan correlation processed image data and the first scan correlation processed image data using the first scan correlation processed image data and the second scan correlation processed image data Is generated and written to the image memory at a raster rendering address to be described later. In parallel with these drawing operations, the data is read out in synchronization with the scanning of the display and displayed as an image on the display. The generation of the transition data is repeated until the next timing signal for the corresponding pixel is input. As a result, the display displays an image that gradually changes from the second scan correlation processed image data to the first scan correlation processed image data over time.
[0020]
The radar apparatus and similar apparatus of the present invention are characterized in that the first scan correlation processing means outputs received data without performing a scan correlation process.
[0021]
In this configuration, when shifting from the second scan correlation processed image data to the first scan correlation processed image data, since the first scan correlation processed image data is the received data, substantially, An image that gradually changes from the second scan correlation processed image data to the received data is displayed.
[0022]
The radar apparatus and the similar apparatus according to the present invention are characterized in that the transition image data generating means includes an adder / subtracter or a multiplier, and an addition / subtraction process or a multiplication process is used for the generation calculation of the shift data.
[0023]
In this configuration, the generation operation of the transition image data is facilitated by performing the generation operation of the transition data by an adder / subtracter or multiplier having a simple configuration.
[0024]
The radar apparatus and the similar apparatus of the present invention are characterized in that a plurality of transition data are simultaneously generated and stored by the transition image data generation means.
[0025]
In this configuration, since a plurality of pieces of transition data are generated and stored simultaneously, the generation and storage speed of the transition data is increased, so that the number of generations and storages of the transition data during one rotation of the antenna increases.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
A radar apparatus according to a first embodiment of the present invention will be described with reference to FIGS.
[0027]
FIG. 1 is a block diagram showing the configuration of the main part of a radar apparatus according to this embodiment. The radar antenna 1 transmits a pulsed radio wave to the outside at a predetermined transmission / reception period while rotating the horizontal plane at a predetermined rotation period, receives the radio wave reflected by the target with a polar coordinate system, and outputs a reception signal to the receiving unit 2 Then, the sweep angle data is output to the radial drawing address generator 5. The receiving unit 2 detects and amplifies the received signal from the radar antenna 1 and outputs the amplified signal to the AD converting unit 3. The AD converter 3 converts the analog reception signal into a digital signal (reception data) composed of a plurality of bits. The sweep memory 4 stores the digitally converted received data for one sweep in real time, and stores the received data for one sweep in the scan correlation processing unit 7 until the received data obtained by the next transmission is written again. Output.
[0028]
The radial drawing address generation unit 5 uses the center of the sweep as the start address, and from the center toward the periphery, the antenna angle θ with reference to a predetermined direction (for example, the bow direction) and the read position r of the sweep memory 4 An address for designating the pixels of the image memory arranged in the orthogonal coordinate system is created. The relationship between the polar coordinate system and the orthogonal coordinate system is shown in FIG. As shown in FIG. 2, when the center address of the sweep is (Xs, Ys), r is the distance from the center, and the angle of the sweep (radar antenna 1) is the address (X, Y) indicating the pixel of the image memory. Is expressed by the following equation.
[0029]
X = Xs + r · sin θ
Y = Ys + r · cos θ
Specifically, the radial drawing address generation unit 5 is configured by hardware that realizes the above equation.
[0030]
The radial drawing address generation unit 5 receives the ship's heading, speed, latitude and longitude, and performs address generation processing that stabilizes the ship's attitude and movement.
[0031]
The FIRST / LAST detection unit 6 applies this sweep to each pixel of the orthogonal coordinate system set by the radial drawing address generation unit 5 on the respective image memories 8 and 13 within one rotation of the sweep (radar antenna 1). The first access time or the last access time is detected, and one of these timings is given to the scan correlation processing unit 7 and the selectors 10 and 12. This is because it is necessary to limit the update of each pixel of the image memory for scan correlation processing to only once per sweep rotation, and therefore, the FIRST signal or the LAST signal is used as this timing.
[0032]
As described above, since it is sufficient to perform one sweep once for the pixel update, it is sufficient to perform either FIRST detection or LAST detection. In the following description, the case of FIRST detection is shown. Hereinafter, a signal output at the FIRST timing is referred to as a “FIRST signal”.
[0033]
Based on the FIRST signal input from the FIRST / LAST detector 6, the scan correlation processor 7 receives the received data input from the sweep memory 4 and the sweep correlation stored in the scan correlation processing image memory 8 described later. The scan correlation process is performed using the image data before one rotation, and the scan correlation process image memory 8 stores the scan correlation process again.
[0034]
In this scan correlation process, the received data input from the sweep memory 4 is N (t), and the pixel position corresponding to the received data obtained from the correlation process image memory 8 during the previous one rotation is input. If the scan correlation processed image data is W (t−1), the scan correlation processed image data W (t) during one rotation this time is calculated using the following equation.
[0035]
W (t) = α · N (t) + β · W (t−1)
Here, α and β are arbitrary numbers.
[0036]
This processing is continued, and the scan correlation processing image data is updated as needed. Then, by setting α and β to predetermined values, it is possible to emphasize received data from a desired target and suppress other targets and unnecessary components.
The scan correlation processing image memory 8 has a capacity for storing received data (scan correlation processing image data) for one rotation of the sweep (radar antenna 1), and the correlation processing image before one rotation is used for the scan correlation processing. The data is fed back to the scan correlation processing unit 7 and output to the transition data generation unit 11.
[0037]
As shown in FIG. 3, the raster drawing address generation unit 9 creates an address of each pixel in the orthogonal coordinate system on the display image memory 13. In FIG. 3, X ′s and Y ′s are the coordinates of the start point, m is the number of pixels in the Y direction from the raster address start point on the display image memory 13, and n is the raster address start point on the display image memory 13. The number of pixels in the X direction, and the address (X, Y) of each pixel on the display image memory 13 is expressed by the following equation.
[0038]
X = X's + n
Y = Y's + m
The selector 10 inputs the FIRST signal from the FIRST / LAST detection unit 6, the radial drawing address from the radial drawing address generation unit 5, and the raster drawing address from the raster drawing address generation unit 9, and the FIRST signal is input. In the case (FIRST = 1), the radial drawing address is output to the scan correlation processing image memory 8 and the display image memory 13 for the radial drawing of the received data, and when the FIRST signal is not input (FIRST = 0). A raster drawing address is output to the scan correlation processing image memory 8 and the display image memory 13 for raster drawing of the data subjected to the scan correlation processing.
[0039]
As shown in FIG. 4, the transition data generation unit 11 includes a comparator 51 and an adder / subtractor 52, and scan correlation processed image data a from the scan correlation processing image memory 8 input to the comparator 51. The display image data b stored in the display image memory 13 to be described later and fed back is compared, and a value k between these absolute values | b−a | and “0” (0 <k). <| B−a |) is output to the adder / subtractor 52. The adder / subtractor 52 inputs the input k and the display image data b, adds / subtracts the display image data b and k using the following expression, and outputs the resulting transition data c to the selector 12.
[0040]
Here, the addition / subtraction is performed when a (scan correlation processing image data) <b (display image data),
c = b−k, and
When a (scan correlation processed image data)> b (display image data),
The calculation of c = b + k is performed.
This calculation is repeated at a predetermined cycle, and each time the calculation is repeated, the display image data gradually approaches the scan correlation processed image data.
In the above description, k is determined by b and a, but may be set to a predetermined value (for example, “1”) in advance.
[0041]
The selector 12 receives the received data from the sweep memory 4, the transition data from the transition data generation unit 11, and the FIRST signal from the FIRST / LAST detection unit 6. When the FIRST signal is input (FIRST = 1) The received data is output to the display image memory 13, and when the FIRST signal is not input (FIRST = 0), the transition data is output to the display image memory 13.
[0042]
For example, the number of rotations of the radar antenna 1 is 24 rpm, the number of radial pixels on one sweep is 512, the number of pixels of the display image memory 13 (raster drawing number) is 1024 × 1024 = 1048576, and one pixel Per drawing speed is 0.1 μsec. In this case, since the number of radial pixels on the sweep is 512, the number of pixels drawn at the FIRST signal input timing during one rotation of the antenna (radial drawing number) is at most 512 × 512 × π = 823550 pixels. . When all of these are drawn, the required time is 823550 × 0.1 (μsec.) = 0.08 sec. Since the antenna rotation speed is 24 rpm, the rotation period of the antenna is 2.5 sec. Therefore, at least 2.5-0.08 = 2.42 sec. Can be used. Since the transition data rendering number (raster rendering number) is 1048576, even if all pixels are rendered, 1048576 × 0.1 (μsec.) = 0.1 sec. Therefore, the transition data can be drawn about 2.42 (sec.) / 0.1 (sec.) = 24 times during one rotation of the antenna. That is, the transition data of each pixel can be generated about 24 times during one rotation of the antenna.
Actually, it is necessary to consider the time of display access to the image memory for displaying on the display, but the time required for display access is omitted in the above calculation.
[0043]
The display image memory 13 has a capacity for storing image data (received data and transition data) for one rotation of the sweep (radar antenna 1), and feeds back the stored image data to the transition data generation unit 11. The display image memory 13 draws image data with a radial drawing address when the FIRST signal is input to the selector 12, and draws image data with a raster drawing address during a period when the FIRST signal is not input to the selector 12. To do. When the display 14 is scanned by a display control unit (not shown), the display image memory 13 outputs the drawn image data as display data in synchronization with the scanning.
[0044]
Here, the transition data generator 11, the selector 12, and the display image memory 13 constitute the transition image data generation means of the present invention.
[0045]
With such a configuration, it is possible to output the received data and the shift data in parallel during one rotation of the antenna, and gradually shift the shift data from the received data to the scan correlation processing image data. it can.
[0046]
For example, as shown in FIG. 5, the change in the pixel value of the pixel in which the target is detected is radially drawn with a pixel value corresponding to the intensity of the received data at a certain FIRST signal input timing. And the pixel value of the corresponding pixel in the scan correlation processed image data for one rotation this time composed of the scan correlation processed image data before one rotation, and the raster drawing is repeated repeatedly. If the target is detected again at the next FIRST signal input timing, the pixel value is radially drawn with a value corresponding to the intensity of the received data.
[0047]
With this configuration, a display image as shown in FIG. 6C can be obtained.
FIG. 6A shows a display image consisting only of received data, and FIG. 6B shows a display image consisting only of scan correlation processed image data. FIG. 6C shows a display image by the radar apparatus shown in the present embodiment.
As shown in FIG. 6, an image based on received data and an image subjected to scan correlation processing exist on the display image, and the scan correlation processed image is gradually changed from the image based on received data in a direction reverse to the rotation direction of the sweep. It changes to an image by data.
[0048]
Thereby, the operator can observe both the image not subjected to the scan correlation process and the image subjected to the scan correlation process.
[0049]
For example, other ships moving at high speed can be captured by an image based on received data that can confirm the current surrounding conditions, and a fixed object such as a buoy can be captured by an image subjected to scan correlation processing. Furthermore, although the clutter such as sea surface reflection is displayed in the image based on the received data, it is not displayed in the image subjected to the scan correlation processing, so that it is possible to identify the clutter such as the sea surface reflection and the desired target based on this. it can.
[0050]
Further, since the received image data and the data subjected to the scan correlation process are displayed at the same time, even when performing GAIN, STC, and FTC adjustment, the adjustment result can be confirmed immediately, and the adjustment operation becomes easy.
[0051]
In addition, since the image based on the received image data and the image based on the scan correlation processed image data can be viewed almost at the same time, there is no need to switch to an optimum image or wait until the processing result is displayed after switching.
[0052]
Further, since an image that gradually changes from the image based on the received image data to the image based on the scan correlation processed image data is displayed, the information obtained by the operator increases. In particular, by observing the changing image, it is possible to prevent the scan correlation processing content from being appropriate and the desired target image from disappearing.
[0053]
In addition, since the image based on the received image data and the image based on the scan correlation processing image data can be viewed almost simultaneously, it is possible to easily and immediately confirm whether the set scan correlation processing content is appropriate.
[0054]
In the description of the present embodiment, the scan correlation processing image memory and the display image memory are configured as separate physical memories, but may be configured within the same physical memory. Thereby, the components of the radar apparatus can be reduced, and the cost of the apparatus can be reduced.
[0055]
Next, a radar apparatus according to the second embodiment will be described with reference to FIG. FIG. 7 is a block diagram showing the configuration of the main part of the radar apparatus according to the present embodiment. The same components as those in the radar apparatus shown in FIG. To do. In the present embodiment, the case where the FIRST signal is used will be described.
[0056]
Based on the FIRST signal input from the FIRST / LAST detection unit 6, the second scan correlation processing unit 27 stores the reception data input from the sweep memory 4 and the second scan correlation processing image memory 28 described later. The scan correlation processing is performed using the image data before one rotation of the sweep, and the result is output to the selector 12. The second scan correlation processing image memory 28 is supplied with the radial drawing address from the radial drawing address generation unit 5, stores the data output from the second scan correlation processing unit 27, and the second scan correlation processing image memory 28 stores the data output from the second scan correlation processing unit 27. This is fed back to the scan correlation processing unit 27. Here, the operation of the second scan correlation processing unit 27 is the same as that of the scan correlation processing image memory 28 in the description of the scan correlation processing unit 7 shown in the first embodiment. It is the same as that replaced with. The first scan correlation processing unit 7 and the second scan correlation processing unit 27 change the correlation processing contents by making the coefficients α and β different.
[0057]
The selector 12 receives the second scan correlation processed image data from the second scan correlation processing unit 27, the transition data from the transition data generation unit 11, and the FIRST signal from the FIRST / LAST detection unit 6, and receives the FIRST signal. When the signal is input (FIRST = 1), the second scan correlation processing data is output to the display image memory 23. When the FIRST signal is not input (FIRST = 0), the transition data is displayed as the display image memory. To 23.
[0058]
The display image memory 23 has a capacity for storing image data for one rotation of the sweep (radar antenna 1), and feeds back the image data stored in the transition data generation unit 11. The display image memory 23 draws image data with a radial drawing address when the FIRST signal is input to the selector 12, and draws image data with a raster drawing address during a period when the FIRST signal is not input to the selector 12. To do. When the display 14 is scanned by a display control unit (not shown), the display image memory 23 outputs the drawn image data as display data in synchronization with the scanning.
[0059]
Here, the transition data generation unit 11, the selector 12, and the display image memory 23 described above correspond to the transition image data generation means of the present invention.
[0060]
With such a configuration, when displaying the first scan correlation process and the second scan correlation process, the second scan correlation process image data is drawn using the radial drawing address at the FIRST signal input timing. Then, the transition data that gradually approaches the first scan correlation processing image data is drawn using the raster drawing address in other periods.
An example of a display image formed by the configuration of the present embodiment is shown in FIG.
FIG. 8A shows only the first scan correlation processed image data, FIG. 8B shows only the second scan correlation processed image data, and FIG. A display image obtained by the configuration is shown in this embodiment. Here, the first scan correlation process is set to detect a target (high-speed ship) that moves at high speed, and the second scan correlation process is set to detect a fixed target (buoy, etc.). Indicates the case.
[0061]
As shown in FIG. 8C, when the configuration of the present embodiment is used, an image of a buoy that is a fixed target is first observed, and then the buoy image gradually disappears and at the same time, a high-speed moving target. An image of a high-speed ship is displayed.
[0062]
In addition, since the image based on the first scan correlation processed image data and the image based on the second scan correlation processed image data can be viewed substantially at the same time, the image is switched to an optimum image, or the processing result is displayed after switching. No need to wait until.
[0063]
Further, since an image that gradually changes from an image based on the second scan correlation image data to an image based on the first scan correlation processing image data is displayed, the information obtained by the operator increases. In particular, by observing a changing image, it is possible to prevent the scan correlation processing content from being a content but not a desired target image from disappearing.
[0064]
In the description of the present embodiment, by setting β = 0 in the first scan correlation process, the first scan correlation processing unit outputs the transition data generation unit without performing the scan correlation process. As a result, it is possible to output image data that gradually changes from the second scan correlation processed image to the raw reception data.
[0065]
In the description of the present embodiment, the first scan correlation processing image memory and the display image memory are configured as separate physical memories, but may be configured within the same physical memory. Thereby, the components of the radar apparatus can be reduced, and the cost of the apparatus can be reduced.
[0066]
Further, in each of the above-described embodiments, the generation and drawing of the transition data to be raster-drawn are performed in units of one pixel. However, the generation and the drawing are performed in units of a plurality of pixels by collectively processing the transition data of consecutive addresses. You may go. By adopting such a configuration, it is possible to shorten the generation and drawing time of the entire transition data, and it is possible to further increase the number of generations and drawing of the transition data during one rotation of the antenna.
[0067]
Further, in each of the above-described embodiments, the radar apparatus has been described. However, the above-described configuration can be applied to an apparatus that displays received data obtained in a polar coordinate system in an orthogonal coordinate system, and an effect due to this can be expected.
[0068]
In each of the above-described embodiments, for the sake of simplicity, the compass, the ship speed, and the latitude / longitude are not input. However, in an actual apparatus, scanning with the direction and position stabilized by these signals is performed. It is desirable to perform correlation processing. However, the display image memory may be operated in a head-up, course-up, or north-up relative motion depending on the usage application of the operator. In this case, since the drawing reference is different between the scan correlation processing image memory and the display image memory, a dedicated raster drawing address generation unit is provided for each. Then, by setting the advancing direction of the drawing address in these raster drawing address generators to a desired angle, it is possible to correspond to each pixel even if the scan correlation processing image memory and the display image memory have different modes. Can be made.
[0069]
【The invention's effect】
According to the radar apparatus and the similar apparatus of the present invention, an image that gradually changes from raw received data to scan correlation processed image data over time during one rotation of the sweep is displayed on the display. The status of the raw target that has not been processed and the status of the desired target that has been subjected to the scan correlation processing can be observed simultaneously. Further, by simultaneously observing the received data, the scan correlation processing image data, and the transition data of values between them, it is possible to easily and immediately confirm whether the set scan correlation processing contents are appropriate. Further, it is possible to easily adjust the scan correlation processing contents while observing this.
[0070]
Further, according to the radar apparatus and the similar apparatus of the present invention, an image that gradually changes from the second scan correlation processed image data to the first scan correlation processed image data as time passes is displayed on the display. Therefore, if these scan correlation processing contents are different, it is possible to simultaneously observe a fixed target such as a buoy and another ship moving at high speed on the same display screen.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a main part of a radar apparatus according to a first embodiment.
FIG. 2 is a schematic diagram showing a radial drawing address.
FIG. 3 is a schematic diagram showing a raster drawing address.
FIG. 4 is a schematic diagram for explaining the operation of a transition data generation unit
FIG. 5 is a diagram showing temporal transition of pixel values of pixel data in a display image memory.
FIG. 6 is a diagram showing a display image when the configuration of the first embodiment is used.
FIG. 7 is a block diagram showing a configuration of a main part of a radar apparatus according to the second embodiment.
FIG. 8 is a diagram showing a display image when the configuration of the second embodiment is used.
FIG. 9 is a block diagram showing a configuration of a main part of a conventional radar apparatus.
[Explanation of symbols]
1,101-Radar antenna
2,102-Receiver
3,103-AD converter
4,104-sweep memory
5,105-Drawing address generator (radial drawing address generator)
6,106-FIRST / LAST detector
7-scan correlation processing unit (first scan correlation processing unit)
27-second scan correlation processing unit
28-second scan correlation image memory
8-Image memory for scan correlation processing
9-Raster drawing address generator
10,12-selector
11-Transition data generator
13,23-Image memory for display
14,109-Display
107-correlation data generator
108-Image memory for correlation processing

Claims (5)

  Radar provided with scan correlation processing means for performing correlation processing between the pixel data of the current received data obtained by rotating the sweep and the previous data of the stored pixel data to generate scan correlation processing data In the apparatus and the similar apparatus, the reception data and the scan correlation processing data are input, and the reception data is output as image data at a predetermined timing during one rotation of the sweep. A radar apparatus and a similar apparatus, characterized by comprising transition image data generation means for generating transition data having values between them based on scan correlation processing data and outputting them as image data.   Radar provided with scan correlation processing means for performing correlation processing between the pixel data of the current received data obtained by rotating the sweep and the previous data of the stored pixel data to generate scan correlation processing data In the apparatus and the similar apparatus, two scan correlation processing means are provided, the first scan correlation processing data generated by the first scan correlation processing means, and the second generated by the second scan correlation processing means. The second scan correlation processing data is output as image data at a predetermined timing during one rotation of the sweep, and the first and second scan correlation processing data are output during a period other than the predetermined timing. A transition image data generation means for generating transition data having a value between them based on the above and outputting as image data The radar or similar apparatus, characterized by comprising.   The radar apparatus and similar apparatus according to claim 2, wherein the first scan correlation processing means outputs the received data without performing a scan correlation process. The radar apparatus and the similar apparatus according to claim 1, wherein the transition image data generation unit includes an adder / subtracter or a multiplier, and an addition / subtraction process or a multiplication process is used for the generation calculation of the transition data.   The radar apparatus and the similar apparatus according to claim 1, wherein the transition image data generation unit generates a plurality of transition data simultaneously.

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